Having watched Tornado being shunted onto a siding the first thing I did was head back inside to find some coffee, at which point I saw my first working model of the day; an LMS Garratt made from Meccano. While not as impressive as a real Garratt in steam this video should give you an idea of just how big these locomotives were when they were in use on the British mainline. Unfortunately none of these locomotives were preserved, although there is a standard gauge Garratt (I think a South African one) in the Power Hall at the Museum of Science and Industry in Manchester which is worth seeing (I was there for a wedding and couldn't get a useable photo).
Strangely having never seen a model of a Garratt in the flesh before there were actually two others making appearances on different layouts at Barrow Hill Live; an O gauge and an N gauge one. But details of the layouts on show can wait for another post.